Screw-contact device.



R. B. BtNJAMlN.

SCREW CONTACT DEVICE.

.wma-mou FILED sEPT.1o.19\a.

1 ,290,053. Patented Jan. T, 1919.

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BEUBIJN B. BENJAMIN, OF CHICAGO, ILLINOIS, ASSIGNOB '.LCi BENJAMIN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SCREllV-CONTACT DEVICE.

Patented Jan. 7, 1919.

Application filed September 1915. Serial No. 49,985.

To all whom t 'may concern:

Be it known that. I, Rennen B. BnNJAMiN, a citizen of the United States, residinigf at Chicago, in the county of Cook and State 5 of Illinois, have invented new and use't'nl Improvements in Screw-Contact Devices, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying' drawing, forming a 1G part of this specification.

My invention relates tdma screw contact device.

One of the objects of iny invention is to `provide an improved screw contact which -an bo t'ornicd, b v stannoing.

Further objects will appear from the detailed description to follow aud troni the appended claims.

In the drawings, in which I have shown three einbi'idiineuts of iny invention Figure. 1 is a side elevation oil part ot an attachment plugprovided with my iniprovedA screw contact;

` Fig. 2 is an axial section ot the plug of Fig. 1;

Fig, 3 is a plan. view ot" the ot Fig. 1;

Fig. 1 is a plan view of a rnoditied forni of screw contact embodying;F iny invention; Fig. 5 is a side elevation of Fig. fi, and Fig. G is a side elevation' of an attachment. plug provided with still another forni of screw contact.

Referringnow to the drawings in detail and .first to Figs. 1, Q and il, the part of the plug shown herein comprises an insulating base 1() `t'or supportingl and coinlnctors. a threaded contact 11 resting on the upper end ot the base 10, a cap or button 12 between which and the base 10 the contact, 11. is clamped. a dishcd center contact 13 snpported on the button 12 and in'- sulated troni the contact 11 by ineans of aid but-ton, a screw 1iA extending through the center contact 13 and through f ipeninggs in the button 12 and hase 10 tor holding the parts in position and :forming part. oi the circ-nit, and a condnctm 1V) in contact. with the .threaded contact 11.

VThe threaded contact 11 comprises a heli- `cal edge 16 t'or engagement with the screw threads of a receptacle. a helical dishcd por tion 17 ad j arent the edge 1G, and a disk portion 17 which is clamped between the base :35 1() and the bntti'm 12. The entering 4portieri screw contact;

the electrical contacts of the helical edge 16 tapers oil' gradually as shown at 18, while the lower end of the helical edge 16 tapers oilA more abruptly as Shown at 1.9. The disk portion 17 is provided with an opening '2O through which the screw 111 extends.

It will be noted that the shape of the helical edge 16 and (lished portieri 17 is snel` that a, forming tool can readily be with drawn from engagement therewith after the contact 11 has been formed by stamping.

In the modification of Figs. 4 and 5 the threaded contact comprises a disk portion 21, a semi-circular portion 22 struck downwardly from the disk portion 21, and a semicircular portion 23 struck upwardly from the disk portion 21, the edges of these two semi-circularportions being shaped to fOrm a helical edge or thread 21 for engagement with the thread of a receptacle. The semicircular portions 2'2 and 253 may be ont away, as indicated at 25 and 26, to facilitate the engagement. of the threaded contact. with4 the threaded receptacle. The disk portion 21 is provided with an 'opening 27 through` which the screw 1/1 may extend. It willibe noted that this contact also can be formen' by stamping.

. In the modification of Fie'. 6 I have shownA the ping provided` with a contact constructed s() that the plug may be connected by a partial turn ot the plug with respect to the receptacle without having' `to screw the plugl all the way in.

In this inoditication the threaded contact 2.8 is similar to the form shown in Figs. l, 2 and 3, but comprises in addition a cylindrical portion 29 at. thenpper end of the plug which. can be inserted. in the receptacle without rotation ot the plug. The lower portion ot the contact 28 is stamped to form a helical edge 30. and a helical dished portion 31 similar to the helical yedge 16 and dished portion 17 of the forni of Figs. 1, 2 and 3.

In this niodication also the construction 1s such that the forming toolcan be readily withdrawn from the contact 38 after the latter has been formed by stamping.

Having thus described my invention what I claim asnew and desire to secure by Letters Patent isz- It. In a device of the class described, an insulating base and a threaded contact of sheet vmaterial supported by Saidbase, said Contact having a peripheral helical edge located at substantially the crest of the thread, whereby said threads may be formed by a die moving axially with respect to said threaded contact and whereby said die may be withdrawn by axial movement without interference from said threads.l

2. A threaded contac `:of Sheet metal, said sheet metal having a pheripheral helical edge located at substantially the crest of the thread whereby said threads may be formed by a die moving axially with respect to said threaded Contact and whereby said die may be withdrawn by'axial movementwithout interference from said threads.

3. A threaded contact of sheet metal, said sheet metal having a peripheral helical edge located at substantially the crest of the thread and a dished portion adjacent said edge, whereby said threads may be formed by a die moving axially with respect to said threaded contact and whereby said die may' be withdrawn by axial movement without interference from said threads.

4. A threaded contact of sheet metal, said sheet metal having a peripheral helical edge located at substantially the crest of the threadand a helical dished portion adjacent said helical edge, whereby `said threadspmay be formed by a die moving axially with respect to said threaded contact and whereby said die may be Withdrawn by axial move` ment without interference from said threads.

In witness whereof, I have hereunto subscribed my name.v

- REUBEN B. BENJAMIN. 

